Process of treating artificial thread



Patented Sept. 19, 1933 PATENT OFFICE PROCESS OF TREATING ARTIFICIAL THREAD Louis Maug, Lyon, France, assignor to Du Font Rayon Company, New York, N. Y., a corporation of Delaware No Drawing.

Application April 23, 1931 Serial No. 532,282

11 Claims.

This invention relates to the treatment of threads of artificial silk or fabrics containing them, and.more particularly to a process for imparting to the materials certain dull effect and/or woolly appearance and feel.

The United States Patent 1,778,327 discloses a process for producing dull effects on threads or filaments of artificial silk, particularly of the cellulose acetate variety, or fabrics containing the same, which comprises first treating at ordinary temperature the materials with an aqueous solution containing to 30% of a chloride of a light metal, such as calcium, magnesium or lithium, and then subjecting the thus treated materials to the action of a hot aqueous acid bath, the concentration of which does not exceed N/10.

I have found that insteadof using a dilute solution of a mineral or an organic acid, I can secure a product characterized by'a white mat appearance without' marked curling by using a dilute aqueous solution of a salt of the type which yields a solution having an acid reaction, such as, for example, acid salts or salts which are easily hydrolyzed at an elevated temperature to yield solutions having acid reactions.

It is thereforean object ,of this invention to provide a method of producing artificial thread having 'a mat appearancebyfirst treating the material with an aqueous solution of a light metal chloride, preferably'of a concentration of from 10% to 3 O%, and then treating the material with a hot dilute solution of a salt of the type which yields a solution-having an acid reaction, the concentration of said salt solution being preferably not in excess of N/ 10.

. Another andspecific object of this invention is to provide; a method of imparting to cellulose acetate artificial silk a mat, delustered and dull appearance by treating the artificial silk in the form of threads or fabrics with a solution containing 10%-30% of a light metal chloride and then with a hot aqueous solution containing an alkali bisulphate in a concentration not to exceed N/lO.

Other objects will appear from the following description and appended claims.

In accordance with the principles of this invention, artificial thread formed of a cellulose derivative, such as cellulose acetate in the form of filaments, threads or fabrics, are first treated with an aqueous solution of a light metal chloride and then with a salt solution, preferably at an elevated temperature, for the purpose of im-- parting to the materials a white, mat and dull appearance without marked curling and without whizzed and dried. The product is characteraifecting the other desirable properties of the material.

As the light metal chloride solutions employed in the first step of the process, this invention contemplates the use of an aqueous solution of chlorides of calcium, magnesium or lithium. In the preferred form of the process, the quantity of the light metal chloride may vary from approximately 10% to 30%. Preferably, the treatment with these solutions is carried out'at normal temperature.

As the salts which may be employed in the second step of the process, I propose to use acid salts or salts which in aqueous solutions are easily hydrolyzed at elevated temperatures, such as at approximately the boiling point, to yield solutions having an acid reaction. The expression salt of the type which yields a solutionhaving an acid reaction" is employed throughout this specification to embrace these two classes of salts. As illustrative examples of acid salts which have given satisfactory results, there may be mentioned sodium bisulphate, potassium bisulphate and similar salts of sulphuric acid. Aluminum sulphate, potassium alum, aluminum chloride, magnesium chloride, zinc chloride and aluminum acetate may be mentioned as illustrative of salts which hydrolyze at elevated temperatures to yield. solutions having an acid reaction.

In the preferred modification of the method, the salts are dissolved in water to form solutions, the concentrations of which do not exceed N/ 10. The treatment of the materials with these solutions is carried out at an elevated temperature, such as, for example, at approximately the boiling point of the aqueous solution.

In order to more clearly explain the invention, the following examples are hereinafter set forth. It is to be understood that these examples merely illustrate two of the various forms of the method constituting this invention:

Example I.-25 kgs. of cellulose acetate threads are immersed for 21 hours in a 20% solution of calcium chloride at a temperature of 25 C. After whizzing, the threads are placed in a vat containing a solution of sodium bisulphate of 2 gr. per liter for 1 hour, the temperature of the solution being approximately at the boiling point thereof. Subsequently, the threads are washed. rinsed, 105

ized by a beautiful dull luster.

Example II.After 25 kgs. of cellulose acetate threads have been immersed for approximatelv 21 hours in a 20% solution of calcium chloride, at

a temperature of 25 0.. the are whizzed and no placed in a vat containing a solution of aluminum sulphate of 5 gr. per liter and maintained therein for 1 hour, the solution being at the boiling point thereof. Subsequentlmthe threads are washed, whizzed and dried. The product possesses a beautiful dull luster.

The process constituting this invention is also applicable to the treatment of mixed fabrics containing, for example, threads of cellulose acetate and threads of regenerated cellulose, .such as those prepared from viscose. When such a mixed fabric is treated in accordance with the procedure outline above in Example I, the properties of the final product are in no wise deleteriously affected, even though the regenerated cellulose threads are sensitive to acids. Y

Since it is obvious that various changes may be made in the specific details hereinbefore set forth, the invention is not restricted thereto except as defined in the appended claims.

I claim:

l. A method of imparting a mat appearance to cellulose acetate artificial threads or fabrics containing the same which comprises first treating the materials with an aqueous solution containing 10% to 30% of a light metal chloride and then with an aqueous-solution of a salt of the type which yields a solution having an acid reaction, the salt solution being at an elevated temperature and the concentration thereof not exceeding N/ 10.

2. A method of imparting a mat appearance to cellulose acetate artificial threads or fabrics containing the same which comprises first treating the materials with an aqueous solution containing 10%-to 30% of a light metal chloride and then with a hot solution containing an alkali bisulphate, the concentration of said second solution not exceeding N/10.

3. A method of imparting a mat appearance to cellulose acetate artificial threads or fabrics containing the same which comprises first treating the materials with an aqueous solution containing 20% of calcium chloride and then with a hot solution containing an alkali bisulphate, the concentration of said second solution not exceeding N/lO.

4. A method of imparting a mat appearance to cellulose acetate artificial threads or fabrics containing the same which comprises first treating the materials withan aqueous solution containing 10% to 30% of a light metal chloride and then with a hot solution containing aluminum sulphate, the concentration of said second solution not exceeding N/ 10.

5. A method of imparting a mat appearance to cellulose acetate artificial threads or fabrics containing the same which comprises first treating the materials with an aqueous solution containing 20% of calcium chloride and then with a hot solution containing aluminum sulphate, the concentration of said second solution not exceeding N 10.

6. A method of imparting a mat appearance to cellulose acetate artificial threads or fabrics containing the same which comprises first treating the materials with an aqueous solution containing 10% to 30% of a light metal chloride and then with an aqueous solution of a salt of the type which yields a solution having an acid reaction, the aqueous salt solution being at approximately the boiling point and of a concentration not exceeding N/10.

'I. A method of imparting a mat appearance to cellulose acetate artificial threads or'fabrics containing the same which comprises first treating the materials with an aqueous solution containing 10% to 30% of a light metal chloride and then with a hot aqueous solution containing an acid salt, the concentration of the second solution not exceeding N/ 10.

8. A method of imparting a mat appearance to cellulose acetate artificial threads or fabrics containing the same which comprises first treating the materials with an aqueous solution containing 10% to 30% of a light metal chloride and then with a boiling solution containing an alkali bisulphate, the concentration of said second solution not exceeding N/10.

9. A method of imparting a mat appearance to cellulose acetate artificial threads or fabrics containing the same which comprises first treating the materials with an aqueous solution containing 20% of calcium chloride and then with a boiling solution containing an alkali bisulphate, the concentration of said second solution not exceeding N/10.

l0. Amethod of imparting a mat appearance to cellulose acetate artificial threads or fabrics containing the same which comprises first treating the materials with an aqueous solution containing 10% to 30% of a light metal chloride and then with a hot aqueous solution containing a salt which hydrolyzes at an elevated temperature to yield a solution having an acid reaction, the concentration of the second solution not exceeding N/ 10. a

11. A method of imparting a mat appearance to cellulose acetate artificial threads or fabrics containing the same which comprises first treating the materials with an aqueous solution containing 20% of calcium chloride and then with a boiling solution containing aluminum sulphate, the concentration of said second solution not exceeding N/ 10.

LOUIS MAUGE. 

